I figured the pliers would crack the top for sure.. wrapped it in cloth with vise grips not too tight - worked fine.

Glad it worked. I have an old semi truck tire inner tube that I cut up to get rubber that use for multiple purposes including opening stuck lids. Go to a truck tire service center and they will give you the throw away inner tubes.

I also make big rubber bands by tying the strip ends together to hold garbage liners in place. You can use a piece to "relax" coiled leaders but it heats the leader and is not recommended for the tippet. You can use it on the butt sections.

After I open a can of varnish and split it into baby food jars I pop one in the microwave for tops 15 sec uncovered for wrapping guides, doesn't smell doesn't explode and I have yet to call 911. Another builder I know sets a can of McClosky's on an electric stovetop to get it hot before he dips. Just be smart about it and don't throw it in on the setting for baked potatos!